Blasting Chamber

ABSTRACT

A blasting chamber capable of conducting painting on a workpiece subsequent to a blasting process in the same working chamber is provided. A dust collection unit  20  that ventilates a main unit  10  during blasting work and a ventilation unit  30  that ventilates a main unit during a painting step are provided. A side wall  11  of the main unit is provided with an entrance  11   a  and an opening-and-closing member  11   b  that opens/closes the entrance, the dust collection unit is provided so as to project from a roof panel  15  to a floor panel  16  at a position closer to an other side wall  12  that is opposed to this side wall so as to partition the interior of the main unit, and a working space  10   a  and a ventilation duct  10   b  are defined in the main unit. A roof panel  15  above a working space has air suction holes  17  formed therein, and an intake opening  22  that communicates between the dust collection unit and the ventilation duct is provided. The side wall is provided with an opening  12   a  that communicates between the ventilation unit and the ventilation duct, and during the blasting process, ventilation is conducted with the dust collection unit with the entrance closed, and during painting, ventilation is conducted with the ventilation unit with the entrance opened.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to blasting chambers or working chambers for a blasting process (in this description, simply referred to as “blasting chambers”), and in particular, to a blasting chamber having formed therein a working space that is large enough so that, when the blasting process is to be conducted on a relatively large-sized workpiece to be processed, one or more workers can enter together with the workpiece and conduct work; and that is adapted to both blasting processing and painting by permitting not only the blasting process, but also painting of the workpiece after the blasting process in the same space.

The term “blasting process” in the present invention is applied in the most broad sense; it includes processes of various types, such as those known as dry ejection or projection (hereinafter referred to as “ejection”, also including projection) in which an abrasive is ejected as a mixed fluid with compressed air and so forth, such as those known as blasting and shot peening; and in addition, the term includes any of those processes in which a projecting material is ejected by centrifugal force, an abrasive or projecting material is ejected by striking a rotating impeller, etc.

In addition, according to the blasting process described above, the abrasive of the present invention widely includes, in addition to abrasive grains and other abrasives for the purpose of polishing or cutting, so-called “shot” that is ejected for the purpose of imparting residual stress to the workpiece, such as steel balls, glass/plastic/ceramic beads and so forth, and powder or particulate matter such as seed shell or kernel that is ejected for various other purposes.

2. Description of the Related Art

Blasting processes in which powder or particulate matter is ejected towards a workpiece, such as those for carrying out cutting or cleaning of the workpiece by ejecting and making the abrasive collide with the workpiece, or those for imparting residual stress to the workpiece by causing shot, such as steel balls, to collide with the workpiece, are utilized in various areas.

With such a blasting process, the working environment is contaminated by scattering of the ejected abrasive, or dust consisting of a crushed powder generated by collision of the abrasive with the workpiece, powder produced by cutting the workpiece, and so forth. Since it is required to collect the abrasive once it is used in order to recycle the abrasive, a working chamber isolated from the rest of the space is generally formed, and the work is performed within this working space.

In addition, also during painting, the surroundings are contaminated by scattered paint particles sprayed by a spray and so forth, or evaporation etc. of the solvent contained in the paint, and at the same time, conversely to this situation, the quality of the painting is deteriorated greatly if foreign matter such as dust particles and so forth enter the working space from the surroundings and adhere to the paint coating. Therefore, in order to prevent the above, a working chamber isolated from the rest of the space is formed, and the painting step is performed in this working space.

When the blasting process described above is conducted as a step prior to painting, an apparatus configuration whereby the blasting process can be followed by the painting step has also been proposed. As one example of an apparatus that enables the painting of a high-pressure gas vessel, such as an LP gas vessel (gas cylinder) and so forth, following the removal of staining after re-examination of the vessel, an apparatus that is provided with a booth for conducting the blasting process and a booth for conducting the painting and that is configured so that the workpiece being conveyed by a conveyor or the like is subjected to the blasting process while the workpiece is passing through the blasting process booth, followed by painting after being conveyed to the painting booth, has also proposed (Japanese Unexamined Patent Publication (KOKAI) No. H08-28793).

As in the above-described '28793, if the workpieces to be processed are relatively small, have the same shape, and require the same processing, like the LP gas cylinders, it is relatively easy to provide a booth for the blasting process and a booth for the painting separately and to conduct the processes by conveying the workpiece to the different booths for each step.

However, if, for example, the workpieces are large and are small-production items, the material or the shape of the workpieces to be processed and the process details are often different at every process; and it is not uncommon for workers to conduct the processes manually for each individual workpiece that is not suitable for processing by a standardized flow process on an assembly line such as the conveyor described above.

Therefore, when the processes are to be conducted on such a workpiece to be processed, a large-sized working chamber equipped with a relatively large working space which the worker can enter together with the workpiece and conduct work is necessary. Thus, if separate working chambers are to be provided for the blasting process and the painting, respectively, it is necessary to ensure an extremely large installation space and to prepare the equipment needed for each process, and thus, a large initial investment will be required. Accordingly, in these circumstances, a blasting process supplier having facilities or equipment suitable for the blasting process of large workpieces conducts the blasting process, and a painter having facilities or equipment suitable for painting large workpieces conducts the painting, respectively, in a cooperative manner.

However, if the work is shared between the different process suppliers for the respective steps in this manner, the workpiece has to be transported/transferred for every work step, resulting in an associated time loss or financial burden.

In addition, if a long period of time is taken for the transportation or the transfer between the blasting process and the painting, staining and so forth may be caused on the surface of the workpiece, and in addition, a contaminant such as grease or the like may also be adhered on the surface of the workpiece due to the contact between the workpiece and workers, transfer machines etc. during the transportation or the transfer. When staining is caused or a contaminant is adhered in this way, work for removing the staining or the contaminant is required before painting.

In light of the above, when the blasting process is conducted on a large workpiece as a pretreatment prior to painting, it would be advantageous if the painting can be conducted after the blasting process has been conducted on the workpiece in the same working chamber where the blasting process has been conducted without moving or transferring the workpiece.

However, the abrasive used for the blasting process or the dust caused during the blasting process etc. is present in the working chamber where the blasting process has been conducted, and so, if the painting is conducted on the workpiece without taking any measures in this working chamber, the abrasive or the dust may be adhered on the paint coating as foreign matter. The adhesion of such foreign matter deteriorates the quality of the painting greatly, and in some cases, the painting itself may have to be repeated.

In addition, when the abrasive ejected within the working chamber is collected and recycled, if this abrasive is contaminated with paint, coloration of the abrasive or adhesion between the abrasive particles due to the paint may occur, and it may not be possible to collect and recycle the abrasive once it is used.

In addition, since the inside of the working chamber becomes contaminated with the scattered dust or fine particles of the atomized paint during both the blasting process and painting, it is required to ventilate the working chamber to keep it clean. The fact that the dust or the fine particles of the paint, which are the substance causing contamination, are required to be removed before discharging such contaminated air from the working chamber is common to the working chambers in which both the blasting process and painting are conducted.

However, contamination within the working space during the blasting process is caused by dust consisting of fragmented abrasive or the powder produced by cutting the workpiece etc., and in addition, contamination within the working space during the painting is caused by the fine particles of the atomized paint ejected by spraying and so forth. Since the substance causing the contamination is different as described above, a suitable method for ventilation and a method for capturing the substance causing the contamination differs between the blasting process and the painting.

Because of the above points, the blasting process and the painting are not conducted within the same working chamber, and in addition, a working chamber configured to enable both the blasting process and painting to be conducted has not been proposed.

The present invention has been conceived in order to overcome the problems in the conventional technologies described above, and with the present invention, it is possible to conduct the blasting process and the painting sequentially in the same working chamber. Thus, an object of the present invention is to provide a blasting chamber that is capable of achieving ventilation by a suitable ventilation method and a suitable method for capturing a substance causing contamination at every step of the blasting process and painting, thus permitting painting to be conducted after the blasting process in the same space.

SUMMARY OF THE INVENTION

A summary of the present invention will be described below together with reference numerals used in the detailed description of the preferred embodiments. These reference numerals are for clarifying the correspondence between the description in the Claims and the description of the Detailed Description of the Preferred Embodiments, and of course, they are not used to construe the technical scope of the Claims of the present invention in a limited manner.

In order to achieve the above object, a blasting chamber 1 of the present invention comprises

a main unit 10;

a dust collection unit 20; and

a ventilation unit 30,

wherein

the main unit 10 defines a space, which is of a rectangular shape etc., with side walls 11 to 14, a roof panel 15, and floor panel 16,

any one side wall 11 of the main unit 10 is provided with an entrance 11 a that allows a workpiece W to be carried in and out and a worker M to enter and exit the chamber and an opening-and-closing member 11 b, such as a door or shutter etc., that opens/closes the entrance 11 a,

a partition wall 25 that is arranged so as to project, in the main unit 10 at a side of an other side wall 12 that is opposed to the one side wall 11, from the roof panel 15 to the floor panel 16 so that a lower end 25 a of the partition wall 25 is separated from the floor panel 16 at the predetermined high position is provided,

a working space 10 a is formed between the one side wall 11 and the partition wall 25 by dividing a space in the main unit 10 with the partition wall 25,

a ventilation duct 10 b, a lower end side of which communicates with the working space 10 a, is formed between the partition wall 25 and the other side wall 12,

a number of air suction holes 17 that introduce outside air into the working space 10 a is formed in the roof panel 15 above the working space 10 a,

the dust collection unit 20 and the ventilation unit 30 each communicate with the ventilation duct 10 b,

the dust collection unit 20 is operated during blasting work, being set so that the intake wind velocity in the ventilation duct 10 b is less than a suspension velocity of an abrasive used at the maximum, sucks the dust suspended in the main unit 10 together with the air in the main unit 10, and discharging clean air after capturing the dust in the air, and

the ventilation unit 30 is operated during a painting step, sucks the paint particles suspended in the main unit 10 together with the air in the main unit 10 with the predetermined intake wind velocity, and discharges clean air from which the paint particles have been removed after capturing the paint particles in the air.

In the blasting chamber 1 of the above-described configuration, the partition wall 25 is formed by arranging either one of the dust collection unit 20 or the ventilation unit 30 (in the embodiment, the dust collection unit 20) so as to project in the main unit 10, and an intake opening of the dust collection unit 20 or the ventilation unit 30 that constitutes the partition wall 25 (in the embodiment, the intake opening 22 of the dust collection unit 20) is formed on the surface of the partition wall 25 opposed to the other side wall 12.

The other side wall 12 may have an opening 12 a formed therein that communicates between the other of the dust collection unit 20 or the ventilation unit 30 (in the embodiment, the ventilation unit 30) and the ventilation duct 10 b.

It is preferable that an intake airflow rate per minute by the dust collection unit 20 be equal to or more than 1.5 times the volume in the main unit 10.

In addition, it is preferable that an airflow velocity in the working space 10 a generated by ventilation by the ventilation unit 30 be equal to or more than 0.4 m/s, and/or

it is preferable that the intake airflow rate by the ventilation unit 30 be 2 to 7 times an intake airflow rate by the dust collection unit 20.

It is possible to provide an abrasive collection unit 40 constituted with an abrasive collecting duct 41, one end of which opens toward the working space 10 a at the lower end position of any one side wall (in the embodiment, the other side wall 12) of the main unit 10; a cyclone 42, an inlet 42 a of which communicates with the other end of the collecting duct 41; and an exhaust duct 43, one end of which communicates with an air outlet 42 b of the cyclone 42 and an other end of which communicates with the ventilation duct 10 b,

a second opening-and-closing means 44 that allows/prevents communication between the exhaust duct 43 and the intake opening 22 of the dust collection unit 20, and

a third opening-and-closing means 45 that opens/closes a flow path in the ventilation duct 10 b below a communication position between the dust collection unit 20 and the ventilation unit 30.

According to the configuration of the present invention described above, the blasting chamber of the present invention is capable of conducting, during the blasting process, ventilation and capturing of dust, according to a contaminated state within the working chamber 1, with the dust collection unit 20 during the blasting process by closing the entrance 11 a and operating the dust collection unit 20 during the blasting process and by opening the entrance 11 a and operating the ventilation unit 30 during painting. During painting, the blasting chamber is capable of conducting ventilation and capturing of paint particles according to a contaminated state within the working chamber 1 with the ventilation unit 30 during painting, and thus, the same working chamber 1 can suitably be used for both the blasting process and the painting.

Furthermore, according to the configuration of the above-described working chamber 1, during the blast processing conducted with the entrance 11 a closed, since the outside air is introduced into the working chamber 1 through the air suction hole 17 formed in the roof panel 15 of the main unit 10, and suction is applied in the working space 10 a at a relatively low position between the lower end 25 a of the partition wall 25 and the floor panel 16 through the ventilation duct 10 b that communicates with the working space 10 a, as shown in FIG. 1 as one example, a downward airflow that acts on an abrasive ejected in the working space 10 a or dust, such as abrasive dust and a fragmented powder of the abrasive generated with the blasting process, so as to push them down to the floor panel 16 side is generated in the working chamber 1; as a result, contamination due to the suspension of the abrasive or the dust can be solved at an early stage. The abrasive or the dust is not easily adhered to the roof panel 15 or the side walls 11 to 14 etc., and thus, a harmful effect whereby abrasive or dust that has adhered to such locations falls on a painted coating and is adhered thereto during subsequent painting is also prevented.

In addition, by setting the intake wind velocity of the dust collection unit 20 so that the wind velocity in the ventilation duct 10 b is less than the suspension velocity of the abrasive, the abrasive can be prevented from being sucked into the dust collection unit 20 during the ventilation by the dust collection unit 20, and the abrasive can be separately collected and recycled.

In addition, by conducting ventilation with the ventilation unit 30 while the entrance 11 a is opened during painting and, as shown in FIG. 3, during painting, by generating an airflow flowing in the working space 10 a from the left side to the right side in the figure, it is possible to make the paint particles move over a relatively long distance in the working space 10 a; the paint particles will dry out during this period, and capturing of the paint particles in the ventilation unit 30 is easy.

In addition, by conducting ventilation while the entrance 11 a is opened, a large amount of air is introduced into the working space 10 a and the inside of the working space 10 a is kept as a clean and hygienic environment.

Therefore, even when both the blasting process and the painting are conducted by using a single working chamber, optimum ventilation is conducted during the blasting process and the painting.

By forming the above-described partition wall 25 with either one of the dust collection unit 20 or the ventilation unit 30 (in the embodiment, the dust collection unit 20) that is arranged in the main unit 10 in a projecting manner, the working chamber 1 can be configured more compact as a whole compared with a case where both the dust collection unit 20 and the ventilation unit 30 are arranged outside the main unit 10.

Here, when the ventilation is conducted by the ventilation unit 30 through the opening 12 a provided in the other side wall 12 during painting in the illustrated embodiment, as shown by white arrows in FIG. 3, since the airflow from the working space 10 a is introduced to the ventilation unit 30 side through the opening 12 a before being introduced into the intake opening 22 side of the dust collection unit 20, the paint particles are made difficult to be introduced into the dust collection unit 20 side even when ventilation by the ventilation unit 30 is conducted while the intake opening 22 of the dust collection unit 20 is opened.

On the other hand, when ventilation is conducted by the dust collection unit 20 during the blasting process, as shown with white arrows in FIG. 1, since the air in the working space 10 a is introduced into the ventilation duct 10 b and is thereafter introduced into the intake opening 22 after the airflow has collided with and been deflected by the other side wall 12, if the ventilation is conducted while the opening 12 a provided in the other side wall 12 is left open, the dust contained in this airflow collides with the capturing means 32, such as the baffle plates 32 a, the secondary filter 32 b and so forth of the ventilation unit 30 through the opening 12 a, and thereby, the filter life of the capturing means 32 may be shortened.

However, by providing the first opening-and-closing means 12 b for opening and closing the opening 12 a (in the embodiment, a cover plate for opening and closing the opening 12 a) as described above, the dust is not introduced into the ventilation unit 30 by shutting the opening 12 a with the first opening-and-closing means 12 b when the ventilation is conducted by the dust collection unit 20, and thus, the filtering function of the capturing means 32, such as the baffle plate 32 a, the secondary filter 32 b, and so forth, provided in the ventilation unit 30 as described above is prevented from being deteriorated.

However, in the illustrated configuration, it is not possible to completely prevent the paint particles from entering the intake opening 22 of the dust collection unit 20 during the ventilation by the ventilation unit 30, and therefore, it is preferable to also provide an opening-and-closing means at the intake opening 22 of the dust collection unit 20, and the intake opening 22 of the dust collection unit 20 may be closed during the ventilation by the ventilation unit 30.

In a configuration in which the positions of the dust collection unit 20 and the ventilation unit 30 are reversed from those of the illustrated embodiment, if the first opening-and-closing means 12 b is provided at the opening 12 a, the air is introduced into the dust collection unit 20 during the ventilation by the ventilation unit 30, and it is possible to prevent the deterioration of the life of the dust collection unit 20, and in this case, an opening-and-closing means for opening and closing an intake opening thereof may further be provided at the ventilation unit 30 side.

By setting the intake airflow rate per minute by the dust collection unit 20 equal to or more than 1.5 times the volume of the main unit 10, even if dust or the like is generated, within a relatively short period of time, the working space 10 a is ventilated and kept clean.

With the configuration in which the paint particle capturing means 32, which is provided in the ventilation unit 30, is equipped with the baffle plates 32 a, since the paint particles are captured by collision with the baffle plates 32 a, the problem of the intake wind velocity being lowered due to clogging does not occur as in the case where particles are filtered out, and thus, it is possible to stably ventilate over a long period of time.

In addition, since the paint particles are captured by a dry-method using the baffle plates 32 a, it is not necessary to carry out complicated work such as treatment of wastewater and so forth, required with a wet-type capturing method, i.e., means for capturing the paint particles by passing the discharged air through water pooled in a water tank, and the maintenance can be conducted with a relatively simple task of exchanging the baffle plates 32 a.

In addition, with a configuration in which an airflow velocity generated by ventilation by the ventilation unit 30 in the working space 10 a is set equal to or more than 0.4 m/s, or, the intake airflow rate by the ventilation unit 30 is set 2 to 7 times the intake airflow rate by the dust collection unit 20, even when the entrance 11 a is opened, the paint particles are prevented from leaking outside the working space 10 a from the entrance 11 a. In addition, it is possible to maintain the interior of the working space 10 a as a clean space by introducing a large amount of outside air into the working space 10 a. By transferring the paint particles with this airflow, the paint particles are more certainly introduced to the ventilation unit 30 and captured before they fall onto the floor panel 16 and adhere thereto.

In addition, with the configuration in which the collection unit is provided, and the second opening-and-closing means 44 and the third opening-and-closing means 45 are provided, the second opening-and-closing means 44 communicates between the exhaust duct 43 and the intake opening 22 of the dust collection unit 20, and the third opening-and-closing means 45 shuts the flow path in the ventilation duct 10 b below the intake opening 22 of the dust collection unit 20. At the same time, by operating the dust collection unit 20, suction is applied in the working space 10 a by the dust collection unit 20 through the ventilation duct 10 b, the exhaust duct 43, the cyclone 42, and the collecting duct 41, and therefore, the abrasive and the dust in the working space 10 a is collected by sweeping the abrasive and the dust disposed on the floor panel 16 with a broom or the like and loaded into the opening portion of the collecting duct 41. Among those, the abrasive to be recycled is collected by the cyclone 42.

In addition, by extending the collecting duct 41 by connecting a hose 47 for collecting the abrasive to the opening portion of the collecting duct 41, the open end of the abrasive collecting hose 47 is moved to appropriate locations in the working space 10 a to suck the abrasive or the dust on the floor panel 16: therefore, it is not necessary for the worker M to conduct a task like sweeping the abrasive or the dust disposed on the floor panel 16 using a broom or the like, as described above.

With the configuration in which an abrasive collecting space 62 is formed between the floor panel 16 and a perforated plate 61, a collection unit 40′ including a dust collector 50 equipped with an air-exhaust ventilator 51 is provided, and a shutting means 63 that shuts the openings in the perforated plate 61 during the painting step is provided, it is possible to conduct collection of the abrasive and the ventilation of the working space 10 a by the dust collection unit 20 simultaneously during the blasting process by applying suction in the collecting space 62 with the air-exhaust ventilator 51 of the dust collector 50, and it is possible to maintain the working space 10 a even more clean.

In addition, by shutting the openings in the perforated plate 61 with the shutting means 63 during painting, it is possible to prevent the paint particles from entering the collecting space 62 and to prevent contamination of the abrasive with the paint: even when the abrasive or the dust remains in the collecting space 62, this abrasive or dust is suitably prevented from being blown upward and contaminating the paint coating.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and advantages of the invention will become apparent from the following detailed description of preferred embodiments thereof provided in connection with the accompanying drawings in which:

FIG. 1 is an explanatory diagram showing a state of a blasting chamber (a first embodiment) of the present invention at the time of a blasting process;

FIG. 2 is a sectional view of FIG. 1 taken along line II-II;

FIG. 3 is an explanatory diagram showing a state at the time of painting in the first embodiment;

FIG. 4 is a perspective view of a ventilation unit;

FIG. 5 is an explanatory diagram showing a state at the time of the blasting process in a second embodiment;

FIG. 6 is an explanatory diagram showing a state at the time of abrasive collection in the second embodiment;

FIG. 7 is an explanatory diagram showing a state at the time of painting in the second embodiment;

FIG. 8 is an explanatory diagram showing a state at the time of the blasting process (used in combination with the abrasive collection) in a third embodiment; and

FIG. 9 is an explanatory diagram showing a state at the time of painting in the third embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A blasting chamber 1 of the present invention will be described below with reference to the attached drawings.

First Embodiment Overall Configuration

Reference numeral 1 in FIGS. 1 to 3 is the blasting chamber of the present invention. As shown in FIGS. 1 and 2, although the overall shape thereof is not particularly limited, this working chamber 1 is made so that workers M can enter together with a workpiece W and conduct work, and the working chamber 1 is provided with a substantially box-shaped main unit 10 that is surrounded by side walls 11 to 14, a roof panel 15, and a floor panel 16; a dust collection unit 20 that ventilates the main unit 10 during the blasting process; and a ventilation unit 30 that ventilates the main unit 10 during painting.

Main Unit

The above-described main unit 10 that constitutes the working chamber 1 of the present invention is a box made of, for example, metal and is formed by two pairs of opposing side walls (11 and 12, and 13 and 14), the roof panel 15, and the floor panel 16. This main unit 10 is formed to have a working space 10 a which the worker M can enter together with the workpiece W to conduct the blasting process and the painting.

A number of air suction holes 17 for introducing outside air into the working space 10 a of the main unit 10 are provided on the roof panel 15 of this main unit 10, preferably, uniformly and at equal intervals over the roof panel 15 positioned above the working space 10 a. When ventilation is conducted by the dust collection unit 20 and the painting air-discharge unit 30 described below and suction is applied in the space within the main unit 10, outside air is introduced downward through the above-described air suction holes 17 provided on the roof panel 15 into the main unit 10.

In addition, the side wall 11 that constitutes one pair (11 and 12) of the above-described two pairs of opposing side walls 11 and 12, and 13 and 14 is provided with an entrance 11 a that allows the workpiece W to be carried in and out and the worker M to enter and exit the main unit 10. An opening-and-closing member 11 b, which is a door or a shutter etc., for opening and closing this entrance 11 a is provided.

In addition, the other side wall 12 that is opposed to the side wall 11 is provided with an opening 12 a, and suction is applied in the main unit 10 by the ventilation unit 30 described below through this opening 12 a.

This opening 12 a is provided with a first opening-and-closing means 12 b, which is a cover plate for opening and closing the opening 12 a, and with this first opening-and-closing means 12 b, the opening 12 a can be closed during the blasting process and can be opened during the painting.

In the illustrated example, although the ventilation unit 30 communicates through this opening 12 a, instead of this configuration, the opening 12 a may be provided so as to communicate with the dust collection unit 20 described below, and the arrangement of the dust collection unit 20 and the ventilation unit 30 may be reversed from the illustrated configuration.

In the above-described main unit 10, a partition wall 25 that is arranged at a position closer to the other side wall 12 described above so as to project from the roof panel 15 toward the floor panel 16 so that a lower end 25 a is located at a predetermined high position with a clearance relative to the floor panel 16 is provided.

As shown in FIG. 2, this partition wall 25 has a width corresponding to the distance between the side walls 13 and 14 that are arranged perpendicular to the side wall 11 on which the entrance 11 a is provided, and the space in the main unit 10 is partitioned by this partition wall 25. The working space 10 a which the worker M enters together with the workpiece W and in which he/she conducts work is formed in the main unit 10 on the side wall 11 side of this partition wall 25, and a ventilation duct 10 b, the lower end of which communicates with the working space 10 a, is formed at the other side wall 12 side of the partition wall 25.

As shown in FIGS. 1 and 3, the lower end portion of the other side wall 12 of the main unit is inclined so as to approach the working space 10 a in the downward direction, and when suction is applied in the ventilation duct 10 b by the dust collection unit 20 or the ventilation unit 30 described below, the airflow flowing into the ventilation duct 10 b from the working space 10 a side can be smoothly introduced into the ventilation duct 10 b.

The above-described partition wall 25 is formed by forming the dust collection unit 20, described below, so as to project into the main unit 10 in the illustrated embodiment, and this partition wall 25 also serves as the casing of the dust collection unit 20. Therefore, the components of the dust collection unit 20, such as a filter (not shown) and so forth, are accommodated within the wall thickness of the partition wall 25.

In the illustrated embodiment, although the partition wall 25 is formed by the casing of the dust collection unit 20, the partition wall 25 and the dust collection unit 20 may be formed completely separately, and, for example, the ventilation duct 10 b may communicate with an opening formed on the side wall of the main unit 10.

In addition, instead of the illustrated configuration, the dust collection unit 20 and the ventilation unit 30 may be arranged in reverse as described above, and the partition wall 25 may be formed by arranging the ventilation unit 30 so as to project into the main unit 10.

A perforated plate (not shown), preferably a relatively thick perforated plate such as a grating or the like, may be laid on the floor panel 16 of the main unit 10 so that the abrasive ejected during the blasting process or the dust generated by ejection of the abrasive that has fallen off and reached the floor panel 16 is trapped in the openings formed in this perforated plate, thereby easily preventing them from being resuspended etc.

In this case, the perforated plate may simply be laid on the floor panel 16 so that it may be removed easily; and during abrasive collection, this perforated plate may be removed from the floor panel 16, and the abrasive deposited on the floor panel 16 may be collected by sweeping with a broom or the like, for example.

Dust Collection Unit

The main unit 10 configured as above is provided with the dust collection unit 20 that performs ventilation of the main unit 10 during the blasting process.

This dust collection unit 20 sucks the air inside the working space 10 a through the above-described ventilation duct 10 b by the operation of the air-exhaust ventilator 21 provided in this dust collection unit 20 and discharges the air sucked from the working space 10 a after the dust has been removed therefrom by passing it through a dust capturing means (not shown) provided inside, such as a filter or the like. As described above, in the illustrated embodiment, by arranging this dust collection unit 20 in a projecting manner from the roof panel 15 side in the main unit 10, the casing of the dust collection unit 20 also serves as the above-described partition wall 25.

As shown in FIG. 2, an intake opening 22 is provided on a side face of the ventilation duct 10 b-side of the partition wall 25, which is the casing of this dust collection unit 20, and the air inside the working space 10 a is introduced into the dust collection unit 20 from this intake opening 22 via the ventilation duct 10 b by the operation of the air-exhaust ventilator 21.

Although not provided in the illustrated configuration, an opening-and-closing means such as a cover plate or the like that opens the intake opening 22 during ventilation by the dust collection unit 20 and that closes the intake opening 22 during the ventilation by the ventilation unit 30 described below is preferably provided.

The air-exhaust ventilator 21 provided in the dust collection unit 20 is set so that the intake wind velocity in the ventilation duct 10 b does not exceed the suspension velocity (in other words except equal to or more than the suspension velocity) of the abrasive used so as not to suck the abrasive deposited on the floor panel 16 of the working space 10 a into the dust collection unit 20 when the working space 10 a is ventilated through the ventilation duct 10 b; and it is preferable to use an air-exhaust ventilator that generates an intake airflow rate of, preferably, 1.5 times the volume within the working chamber 1 per minute or more so as to be capable of ventilating the working space 10 a within a relatively short period of time.

Ventilation Unit

The reference numeral 30 in FIGS. 1, 3, and 4 is the ventilation unit that ventilates the main unit 10 during painting; the ventilation unit communicates with the ventilation duct 10 b in the main unit 10 through the opening 12 a provided on the other side wall 12 of the main unit 10 described above and sucks the air in the working space 10 a through this ventilation duct 10 b.

This ventilation unit 30 sucks the air in the working space 10 a of the main unit 10 by the operation of an air-exhaust ventilator 31, introduces the air to a capturing means 32 for capturing the paint particles contained in this air to capture the paint particles present in an atomized state in the air, and discharges the cleaned air.

In this embodiment, baffle plates (primary filter) 32 a and a secondary filter 32 b arranged downstream of these baffle plates 32 a are provided as the above-described capturing means 32 for capturing the paint particles.

Of these components, the baffle plates 32 a are plates provided upright in the middle of the airflow path, as shown in FIG. 4. In this embodiment, the baffle plates 32 a, which are formed in a substantially U shape in cross section in the width direction, are arranged so as to be alternately engaged with each other in opposite directions, so that most of the paint particles in the air can be captured by causing them to collide with the surface of the baffle plates 32 a while the airflow passes through the clearance formed between the baffle plates 32 a in a snaking manner, as illustrated with arrows in the figure.

A trace of paint particles remaining in the air, which have not been captured by the baffle plates 32 a, is filtered out by the secondary filter, which is a filter of a known type, such as that formed of non-woven cloth and so forth, arranged downstream of the baffle plates 32 a in suction direction by the air-exhaust ventilator 31.

As the above-described air-exhaust ventilator 31 provided in this ventilation unit 30, one capable of generating an airflow velocity equal to or more than 0.4 m/s in the working space 10 a is used, and in addition, one generating an intake airflow rate of 2 to 7 times that of the air-exhaust ventilator provided in the above-described dust collection unit 20 is preferably used; thereby, the fine particles of the sprayed paint are sucked out before reaching the floor surface etc. in the working space and are captured with the painting exhaust unit.

In this embodiment, since the surface of the above-described baffle plates 32 a is specially processed so as to improve the capturing efficiency of the paint particles, the capturing efficiency of the paint particles by the above-described baffle plates 32 a is high, and by employing a double-filtration system with a combination of the above-described baffle plates 32 a and the secondary filter 32 b, it is possible to achieve a high capturing efficiency of equal to or more than 90% for melamine paint and equal to or more than 85% for lacquer primer.

With the configuration of this embodiment where the paint particles are captured by the combination of the baffle plates 32 a, which are a primary filter, and the secondary filter 32 b in this way, since most of the paint particles are captured by the baffle plates 32 a, only a small amount of the paint particles is captured by the secondary filter 32 b, and so, clogging of the secondary filter 32 b does not easily occur; as a result, even if the secondary filter 32 b is used continuously over a relatively long period of time, the intake wind velocity of the ventilation unit 30 is not lowered, and ventilation of the working chamber is conducted successfully.

Furthermore, by capturing the paint particles using a dry method, such as with the baffle plates 32 a and the secondary filter 32 b, it is not necessary to carry out complicated work such as treatment of water used for the capturing and so forth, as in the case of a wet-type capturing method that is conducted by capturing the paint particles in water by passing the discharged air through water pooled in a water tank, and there is an advantage in that the maintenance can be conducted by a simple task of exchanging the baffle plates 32 a or the secondary filter 32 b.

Operation etc.

The operation of the respective parts of the working chamber 1 will be described for the case where the blasting process is conducted on the workpiece W by using the working chamber 1 of the present invention configured as above and where painting is conducted on the workpiece after this blasting process.

Before processing the workpiece W, the opening-and-closing member 11 b provided on the side wall 11 of the main unit 10 of the working chamber 1 is opened, and through which the workpiece W to be processed is carried in to the working space 10 a and through which the worker M who conducts the work enters the working space 10 a.

In the following explanation, although all of the work conducted on the workpiece W will be explained as being conducted by the worker M, the work may be conducted in the unmanned working space 10 a by carrying a working robot or the like into the working space 10 a together with the workpiece W instead of the worker M, for example.

As shown in FIG. 1, when the blasting process is conducted on the workpiece W, the entrance 11 a formed on the side wall 11 is closed by the opening-and-closing member 11 b so as to prevent the abrasive or the dust from leaking from the working chamber 1.

When the opening 12 a provided in the other side wall 12 is closed by the first opening-and-closing means 12 b, the air-exhaust ventilator 21 of the dust collection unit 20 is turned on, and the air-exhaust ventilator 31 of the ventilation unit 30 is turned off, the worker M in the working space 10 a conducts the blasting process by ejecting the abrasive supplied from an abrasive pressurized feeding apparatus (not shown) from the hand held blast gun to the necessary location on the surface of the workpiece W.

By turning on the air-exhaust ventilator 21 provided in the dust collection unit 20, the dust collection unit 20 sucks the air inside the working space 10 a from the intake opening 22 through the ventilation duct 10 b and discharges it outside the main unit 10; thereby, as shown with arrows in FIG. 1, the outside air is introduced downward through the air suction holes 17 provided on the roof panel 15 of the main unit 10 into the working space 10 a where negative pressure has been produced due to the suction applied by this dust collection unit 20.

The air inside the working space 10 a is sucked into the intake opening 22 of the dust collection unit 20 from the clearance between the floor panel 16 of the main unit 10 and the lower end 25 a of the partition wall 25 through the ventilation duct 10 b, and clean air is discharged after the dust contained in the air is removed in the dust collection unit 20.

In this embodiment, as the air-exhaust ventilator 21 provided in the dust collection unit 20, one having a capacity that is capable of generating an airflow rate that enables discharging a volume of air 1.5 times the volume of the space in the main unit 10 per minute is used as one example, and as a result, the dust and so forth generated by the blasting process can be removed immediately, and the working space 10 a is kept clean and comfortable.

Since the introduction of the outside air to the working space 10 a is achieved through the air suction holes 17 formed in the roof panel 15, and the suction of the air inside the working space 10 a is achieved through the ventilation duct 10 b that is formed at a location close to the floor panel 16 in this way, as shown with arrows in FIG. 1, a downward airflow directed towards the floor panel 16 from the roof panel 15 is produced in the working space 10 a.

Therefore, the ejected abrasive and the dust generated during the blasting process move so as to be pushed toward the floor panel 16 by this airflow and fall down and are deposited on the floor panel 16 within a relatively short period of time; thus, once the falling abrasive, dust, and so forth are deposited on the floor panel 16, they are not easily resuspended in the air by being blown upward by the airflow generated by ventilation.

As above, the abrasive and the dust deposited on the floor panel 16 are removed by, for example, sweeping with a broom or the like as needed after the blasting process has finished. As described above, if the perforated plate, such as the grating, is laid on the floor panel 16, the abrasive and the dust deposited on the surface of the floor panel 16 may be collected after removing this perforated plate temporarily.

When the abrasive and the dust are removed by, for example, sweeping with a broom or the like in this way, since there is a possibility that the dust and so forth deposited on the floor panel 16 will be resuspended during this process to contaminate the working space, it is preferred to close the entrance 11 a, to keep the opening 12 a shut with the first opening-and-closing means 12 b, to keep the air-exhaust ventilator 21 of the dust collection unit 20 turned on (keep the air-exhaust ventilator 31 of the ventilation unit 30 turned off), and to continue the ventilation of the working space 10 a.

Instead of conducting such collection of the abrasive, for example, by covering the floor panel 16 (or if a perforated plate such as a grating or the like is laid down, this perforated plate) on which the abrasive and the dust are deposited with, for example, a protective sheet and so forth, the dust and so forth deposited on the floor panel may be prevented from contaminating the paint coating by being resuspended, and the paint is prevented from contaminating the abrasive deposited on the floor panel that will be collected and recycled later, during the painting conducted in the next step.

The painting is conducted on the workpiece W after the blast process has finished in a state that the removal of the abrasive and the dust deposited on the floor panel 16 has been completed and/or, the floor panel 16 has been covered with the protective sheet or the like, as described above.

During painting, as shown in FIG. 3, the ventilation of the working space 10 a by the ventilation unit 30 is conducted by opening the opening 12 a provided on the other side wall 12 of the main unit by operating the first opening-and-closing means 12 b, communicating the ventilation unit 30 with the ventilation duct 10 b, turning on the air-exhaust ventilator 31 provided in the ventilation unit 30, and turning off the air-exhaust ventilator 21 provided in the dust collection unit 20.

At this time, painting of the workpiece W is conducted by spraying the paint when the opening-and-closing member 11 b provided on the side wall 11 of the main unit 10 is opened, the entrance 11 a is opened, and as shown by white arrows in FIG. 3, the airflow flowing from the entrance 11 a towards the opening 12 a is generated.

As mentioned above, when the air-exhaust ventilator 31 provided in the ventilation unit 30 is turned on while the entrance 11 a is opened, not only is the outside air introduced through the air suction holes 17 provided on the roof panel 15, but also a large amount of outside air is introduced through the entrance 11 a into the working space 10 a, and as shown with white arrows in FIG. 3, the airflow flowing from the left side to the right side in the figure is generated in the working space 10 a.

Here, since the paint sprayed in the working space 10 a is in a fine particulate state and has a low weight compared with the abrasive and so forth, the paint is prone to be blown by the airflow generated by the ventilation unit 30 in the working space 10 a, and thus, the paint particles do not leak outside the main unit 10 by the generation of the airflow directed to the opening 12 a side from the entrance 11 a even when the entrance 11 a is left open. In addition, the paint particles are sucked, together with this airflow, into the ventilation unit 30 through the opening 12 a by passing through the working space 10 a and the ventilation duct 10 b before reaching the floor panel 16 and are captured by the above-described baffle plates 32 a and the secondary filter 32 b, and clean air is discharged to the outside.

Furthermore, the paint particles tend to dry out while moving since the paint particles move over a relatively long distance in the working space 10 a, from the entrance 11 a side to the opening 12 a side, and thus, the capturing efficiency of the ventilation unit 30 is improved.

In addition, as described above, since the airflow flowing from the entrance 11 a side to the opening 12 a side is generated in the working space 10 a, even if the abrasive and the dust and so forth that have not been collected remain on the floor panel 16, the abrasive and dust move along the floor panel 16 and are not easily blown upward. As a result, it is possible to prevent the paint coating from being contaminated by the abrasive and the dust.

In particular, since the intake airflow rate of the air-exhaust ventilator 31 provided in the ventilation unit 30 is set to be more than, for example, 2 to 7 times the intake airflow rate of the air-exhaust ventilator 21 provided in the dust collection unit 20, it is possible to keep the working space 10 a clean by introducing a large amount of outside air and to prevent the paint particles from leaking through the entrance 11 a. In addition, it becomes possible to more certainly introduce the paint particles to the ventilation unit 30 without allowing them to reach the floor panel 16.

Second Embodiment

Another example configuration (Second Embodiment) of the working chamber 1 of the present invention will be described with reference to FIGS. 5 to 7.

The working chamber 1 of this embodiment, shown in FIGS. 5 to 7, is provided with a collection unit 40 configured of a collecting duct 41, a cyclone 42, and an exhaust duct 43. The working chamber 1 differs from the working chamber 1 of the first embodiment described above with reference to FIGS. 1 to 4 in that second and third opening-and-closing means 44 and 45 are provided in the ventilation duct 10 b. The remaining configuration is the same as that of the working chamber 1 of the first embodiment described with reference to FIGS. 1 to 4, and therefore, a description of the common parts will be omitted.

The cyclone 42 constituting the above-described collection unit 40 generates a swirling flow therein by the airflow passing through the inside, thereby separating and collecting the abrasive to be recycled by collecting the abrasive having a relatively high weight by making it drop out from the airflow by the centrifugal force so as to be separated and fall down, and by discharging the dust that is lighter, compared with the abrasive, together with the airflow.

The lower end of this cyclone 42 can be provided with an abrasive tank 42 c for pooling the collected abrasive, and in addition, the cyclone 42 may be provided with an abrasive pressurized feeding means (not shown) and so forth for pressurized-feeding the abrasive collected in this tank 42 c to a blast gun disposed in the working space 10 a.

As shown in FIGS. 5 to 7, an inlet 42 a of this cyclone 42 communicates with the working space 10 a through the collecting duct 41. An air outlet 42 b of the cyclone 42 communicates with the above-described ventilation duct 10 b formed in the main unit 10 through the exhaust duct 43.

In this embodiment, the lower end of an opening portion of the collecting duct 41 opens toward the working space 10 a so as to be at the same height as the floor panel 16 of the main unit 10, and as shown in FIG. 6, the abrasive and the dust deposited on the floor panel 16 can be sucked into the collecting duct 41 by the worker M sweeping the abrasive and the dust into the opening portion of the collecting duct 41 using a broom or the like.

In addition, the exhaust duct 43 that communicates with the air outlet 42 b of the cyclone 42 communicates with the above-described ventilation duct 10 b through the roof panel 15 of the main unit 10.

In the ventilation duct 10 b, the above-described second opening-and-closing means 44 and the third opening-and-closing means 45 are provided. Of those, the second opening-and-closing means 44 is for opening and closing the flow path between the exhaust duct 43 and the intake opening 22 of the dust collection unit 20, and in this embodiment, the second opening-and-closing means 44, which is a plate-like member, opens/closes the ventilation duct 10 b at a position above the intake opening 22 of the dust collection unit 20, thereby, allowing/preventing communication between the intake opening 22 of the dust collection unit 20 and the exhaust duct 43.

In addition, the above-described third opening-and-closing means is for opening and closing the flow path in the ventilation duct 10 b at a lower position for both the intake opening 22 of the dust collection unit 20 and the opening 12 a, and this third opening-and-closing means controls the flow of the air to the dust collection unit 20 from the working space 10 a.

As shown in FIG. 6, as a modified example, the opening portion of the above-described collecting duct 41 is configured so that a flexible collecting hose 47 can be connected via an adaptor 46 and so forth. By doing so, the opening portion of the collecting duct 41 may be made extendable. Extending the opening portion of the collecting duct 41 in this way enables a configuration with which collection of the abrasive can be conducted without sweeping the abrasive and the dust deposited on the floor panel 16 of the main unit 10 by moving the open-end of the collecting hose 47 to the locations where the abrasive and the dust are deposited.

As shown in FIG. 5, in the working chamber 1 of this embodiment configured as above, the second opening-and-closing means 44 is positioned so as to block the communication between the exhaust duct 43 and the intake opening 22 of the dust collection unit 20, and the third opening-and-closing means 45 is positioned so as to open the ventilation duct 10 b during the blasting process.

In this state, by closing the entrance 11 a, closing the opening 12 a with the first opening-and-closing means 12 b, turning on the air-exhaust ventilator 21 of the dust collection unit 20, and turning off the air-exhaust ventilator 31 of the ventilation unit 30, the ventilation of the working space 10 a is conducted by the dust collection unit 20, as with the working chamber of the first embodiment described with reference to FIG. 1.

After the blasting process is finished, if the abrasive and the dust deposited on the floor panel 16 of the working space 10 a are to be collected, as shown in FIG. 6, the second opening-and-closing means 44 is operated to communicate the exhaust duct 43 with the intake opening 22 of the dust collection unit 20, and the third opening-and-closing means 45 is operated to shut the flow path in the ventilation duct 10 b.

At this time, the opening 12 a is kept closed by the first opening-and-closing means 12 b, and the air-exhaust ventilator 21 of the dust collection unit 20 is kept turned on and the air-exhaust ventilator 31 of the ventilation unit 30 is kept turned off.

When the communication between the intake opening 22 of the dust collection unit 20 and the working space 10 a is shut off by the third opening-and-closing means 45 in this way, suction cannot be applied in the working space 10 a directly through the ventilation duct 10 b by the dust collection unit 20, whereas the communication between the exhaust duct 43 and the intake opening 22 of the dust collection unit 20 is established; thereby, the dust collection unit 20 starts to apply suction to the working space 10 a through the exhaust duct 43, the cyclone 42, and the collecting duct 41.

Therefore, when the abrasive and the dust deposited on the floor panel 16 are loaded into the opening portion of the collecting duct 41 by, for example, sweeping and so forth, the loaded abrasive and the dust are introduced into the cyclone 42 together with the air inside the working space 10 a through the collecting duct 41. The abrasive contained is removed and collected by the swirling flow generated in the cyclone 42 and is collected in the tank 42 c provided under the cyclone 42.

On the other hand, the air containing the dust from which the abrasive has been removed and collected is introduced into the exhaust duct 43 through the air outlet 42 b of the cyclone 42 and is introduced into the dust collection unit 20 through the ventilation duct 10 b.

In addition, the dust is removed in this dust collection unit 20 and clean air is discharged to the outside.

After collection of the abrasive has finished in this way, when painting is conducted on the workpiece W after the blasting process, as shown in FIG. 7, the second opening-and-closing means 44 is positioned so as to shut off the communication between the exhaust duct 43 and the intake opening 22 of the dust collection unit 20, and the third opening-and-closing means 45 is positioned so as to open the ventilation duct 10 b.

In addition, the opening 12 a that has been closed by the first opening-and-closing means 12 b is opened and the entrance 11 a is opened, and also, the air-exhaust ventilator 21 of the dust collection unit 20 is turned off, and the air-exhaust ventilator 31 of the ventilation unit 30 is turned on. Thereby, the ventilation of the working space 10 a is conducted successfully during painting, as in the first embodiment described with reference to FIG. 3. The ejected paint particles are then captured by the baffle plates 32 a and the secondary filter 32 b provided in the ventilation unit 30, and the clean air is discharged outside.

As described above, by providing the above-described collection unit 40 and the first and third opening-and-closing means 44 and 45 in this embodiment, it is possible to easily remove the abrasive and the dust deposited on the floor panel 16 of the working space 10 a by utilizing the negative pressure generated by the dust collection unit 20, to collect the recyclable abrasive contained therein with relative ease, and further, to discharge the dust remaining in the air from which the abrasive has been collected is removed by the dust collection unit 20.

Third Embodiment

As described above, in the second embodiment described with reference to FIGS. 5 to 7, although ventilation of the working space 10 a by the dust collection unit 20 through the ventilation duct 10 b and collection of the abrasive through the collection unit 40 are conducted alternately, collection of the abrasive from the working space 10 a may be conducted simultaneously with ventilation of the working space 10 a by the above-described dust collection unit 20.

An example configuration of the working chamber 1 configured in this way is described with reference to FIGS. 8 and 9, as a third embodiment.

In the embodiment illustrated in FIGS. 8 and 9, in addition to the collecting duct 41′, the cyclone 42′, and the exhaust duct 43′, the collection unit 40′ is provided with a dust collector 50 equipped with an air-exhaust ventilator 51, and the exhaust duct 43′ communicates with the intake opening of this dust collector 50.

By laying a perforated plate 61, such as a grating or the like, on the floor panel 16 of the main unit 10 with a predetermined clearance between them, a collecting space 62 in which the abrasive and the dust that falls between the floor panel 16 and the perforated plate 61 is captured is formed.

With the configuration of the working chamber 1 of this embodiment shown in FIGS. 8 and 9, members corresponding to the second and third opening-and-closing means 44 and 45 that were provided in the ventilation duct 10 b of the working chamber 1 of the second embodiment described with reference to FIGS. 5 to 7 are not provided.

In the working chamber 1 of this embodiment, configured as above, during the blasting process, as shown in FIG. 8, the opening 12 a is closed with the first opening-and-closing means 12 b, both the air-exhaust ventilator 21 of the dust collection unit 20 and the air-exhaust ventilator 51 of the dust collector 50 are turned on, and the air-exhaust ventilator of the ventilation unit 30 is turned off; thereby, ventilation of the air inside the working space 10 a with suspended dust is conducted by the dust collection unit 20 through the ventilation duct 10 b. The abrasive and the dust which are collected in the collecting space 62 after falling on the floor panel 16 through the openings in the perforated plate 61 are introduced into the collection unit 40′ by the negative pressure generated by the dust collector 50, and the abrasive is collected in the cyclone 42′ of the collection unit 40′.

The air containing dust from which the abrasive has been collected is introduced into the dust collector 50 through the exhaust duct 43′, the dust is captured by a filter provided in this dust collector 50, and the clean air from which the dust has been removed is discharged outside.

On the other hand, during painting, in a state in which the working space 10 a and the collecting space 62 are separated by, for example, covering the perforated plate 61 with a protective sheet or the like so that the paint particles are prevented from entering the collecting space 62, the opening 12 a is closed with the first opening-and-closing means 12 b, both the air-exhaust ventilator 21 of the dust collection unit 20 and the air-exhaust ventilator 51 of the dust collector 50 are turned off, and the air-exhaust ventilator 31 of the ventilation unit 30 is turned on; thereby, ventilation of the working space 10 a can be suitably conducted by the ventilation unit 30, as in the case described in the first and second embodiments.

In the above description, although the working space 10 a and the collecting space 62 are described as being separated by covering the perforated plate 61 with the protective sheet, both spaces may be configured so as to be separated by providing a shutter-like member that slides under the perforated plate 61, for example, and in addition, the separation of both spaces may be performed automatically.

With the working chamber 1 of this embodiment configured as above, it is not necessary to provide a step for removing and collecting the abrasive in the working space 10 a upon transition from the blasting process to the painting, which is advantageous in that the processing time can be shortened further as it is possible to conduct the painting immediately after the blasting process.

In addition, since the abrasive and the dust deposited on the floor panel 16 are collected properly during the blasting process, it is easier to prevent contamination in the working space 10 a due to the resuspension of the abrasive and the dust deposited on the floor panel 16.

Although the detail is omitted, it is possible to improve the efficiency of the abrasive and dust collection without interfering with lowering of the floor height by providing an abrasive collection mechanism in the collecting space 62, which has been proposed by the applicant in Japanese Unexamined Patent Publication (KOKAI) No. 2009-95892, in which a floor panel is divided into a mesh member through which the abrasive can pass, a blasting chamber having the mesh member as a floor surface is formed, a plurality of substantially inverted-quadrangular pyramid shaped hoppers are arranged in lines under the mesh member so that the tops thereof are opened so as to face the mesh member, and the lower ends of each hopper communicates with a suction means (not shown) such as a dust collector or the like through a collection duct.

Thus the broadest claims that follow are not directed to a machine that is configured in a specific way. Instead, said broadest claims are intended to protect the heart or essence of this breakthrough invention. This invention is clearly new and useful. Moreover, it was not obvious to those of ordinary skill in the art at the time it was made, in view of the prior art when considered as a whole.

Moreover, in view of the revolutionary nature of this invention, it is clearly a pioneering invention. As such, the claims that follow are entitled to very broad interpretation so as to protect the heart of this invention, as a matter of law.

It will thus be seen that the objects set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Now that the invention has been described; 

1. A blasting chamber comprising: a main unit; a dust collection unit; and a ventilation unit; wherein the main unit defines a space with side walls, a roof panel, and a floor panel; any one side wall of the main unit is provided with an entrance that allows a workpiece to be carried in and out and a worker to enter and exit the blasting chamber and an opening-and-closing member that opens/closes the entrance; a partition wall that is arranged so as to project, in the main unit at a side of an other side wall that is opposed to said one side wall, from the roof panel to the floor panel so that a lower end of the partition wall is separated from the floor panel is provided; a working space is formed between said one side wall and the partition wall by dividing a space in the main unit with the partition wall; a ventilation duct, a lower end of which communicates with the working space, is formed between the partition wall and said other side wall; a number of air suction holes that introduces outside air into the working space is formed in the roof panel above the working space; the dust collection unit and the ventilation unit each communicate with the ventilation duct; the dust collection unit is operated during blasting work with a set wind velocity in the ventilation duct of less than a suspension velocity of an abrasive to be used; and the ventilation unit is operated during a painting step with a predetermined intake wind velocity.
 2. A blasting chamber according to claim 1, wherein the partition wall is formed by arranging either one of the dust collection unit or the ventilation unit so as to project into the main unit, and an intake opening of the dust collection unit or the ventilation unit that constitutes the partition wall is formed on a surface of the partition wall opposed to said other side wall; and said other side wall is formed with an opening that communicates between the ventilation duct and the other side of the dust collection unit or the ventilation unit.
 3. A blasting chamber according to claim 2, further comprising a first opening-and-closing means that opens/closes the opening.
 4. A blasting chamber according to claim 1, wherein an intake airflow rate per minute by the dust collection unit is equal to or more than 1.5 times a volume of the main unit.
 5. A blasting chamber according to claim 2, wherein the ventilation unit is provided with a baffle plate as a means for capturing paint particles.
 6. A blasting chamber according to claim 1, wherein an airflow velocity in the working space generated by ventilation by the ventilation unit is equal to or more than 0.4 m/s.
 7. A blasting chamber according to claim 2, wherein an airflow velocity in the working space generated by ventilation by the ventilation unit is equal to or more than 0.4 m/s.
 8. A blasting chamber according to claim 1, wherein an intake airflow rate by the ventilation unit is 2 to 7 times an intake airflow rate by the dust collection unit.
 9. A blasting chamber according to claim 2, wherein an intake airflow rate by the ventilation unit is 2 to 7 times an intake airflow rate by the dust collection unit.
 10. A blasting chamber according to claim 1, further comprising: an abrasive collection unit constituted with an abrasive collecting duct, one end of which opens toward the working space at a lower end position of any one side wall of the main unit; a cyclone, an inlet of which communicates with the other end of the abrasive collecting duct; and an exhaust duct, one end of which communicates with an air outlet of the cyclone and an other end of which communicates with the ventilation duct; a second opening-and-closing means that allows/prevents communication between the exhaust duct and the intake opening of the dust collection unit; and a third opening-and-closing means that opens/closes a flow path in the ventilation duct below a communication position between the dust collection unit and the ventilation unit.
 11. A blasting chamber according to claim 10, further comprising a flexible abrasive collecting hose provided so as to be attachable to an opening portion of the abrasive collecting duct.
 12. A blasting chamber according to claim 10, wherein an abrasive collecting space is formed between the floor panel and a perforated plate by laying the perforated plate on the floor panel with a predetermined clearance therebetween in the working space, and the abrasive collection unit is formed by communicating the abrasive collecting duct that opens toward the collecting space with the inlet of the cyclone and by communicating the exhaust duct that communicates with the air outlet of the cyclone with a dust collector equipped with an air-exhaust ventilator, and a shutting means that shuts holes in the perforated plate during a painting step is provided. 